Prevention of pitting and corrosion in steam-boilers, heating-boilers for hot-water circulation, calorifiers, and the like.



G. HAYTHORPE. PREVENTION OF FITTING AND CORROSION IN STEAM BOILERS, HEATING BOILERS FOR HOT WATER CIRCULATION, GALORIFIERS, AND THE LIKE. APPLICATION FILED NOV. 18, 1914.

1,l2?,30, Patented Feb. 2, 1915.

para snares amend en i e,

CHARLES HAYTHORPE, 0:15 KENNINGTON, LONDON, ENG-LAND.

PREVENTION OF FITTING AND CORROSION IN STEAM-BOILERQ HEATING-BOILERS FOR HOT-WATER CIRCULATION, CALORIFIERS, AND THE LIKE.

Specification of Letters Patent.

,Paten-ted Feb. 2, an.

Application filed November 18,1914. 7 Serial No. 872,842.

' To all whom it may concern Green street, Kennington, London, S. E,

England, has invented certain new and useful Improvements for Prevention of Fitting and Corrosion in SteamBoilers, Heating- Boilers for Hot-Water Circulation, Calorifiers, and the like, of which the following is a specification.

This invention relates to the prevention of pitting and corrosion in steam-boilers. Zinc plates, as heretofore proposed for this purpose, are inefficient in that they do not prevent or deal with grease deposits; they do not prevent incrustation; and their action is usually only very local.

Now this invention contemplates the use of composite plates of zinc and carbon, and has for its objects to render such plates highly efficient, constant in action, durable, and productive of a high voltage. To this end, and in accordance with this invention, the zinc plates are made of substantial thickness, say 3;", whereby their life is lengthened and they are enabled to withstand the high temperatures now commonly employed in steam-boilers. Further, according to this invention, the zinc and carbon plates are maintained in close or intimate contact with one another, with the result that they not only act as a more efficient galvanic couple, but the entry of grease and sediment between them, which would impair the galvanic action, can be completely avoided. Also in accordance with this inventiomthe composite plates are arranged in good metallic connection with the boiler.

It is convenient to employ the composite plates of this invention where the feed-water purifier, described and claimed in the specification of Letters Patent No. 1,022,365 granted to me, cannot, owing to want of space, or by reason of expense, or what not, conveniently be used, but, of course, they may be employed in conjunction with said feed-water purifier.

A composite plate constructed in accordance with this invention is highly eiiicient as a diffuser of electrical action throughout the hot water in the boiler even under the severe conditions, in regard to temperature, obtaining in present day practice with steam-generators, but it is rendered still more eflicient by means of the metallic contact between it and the boiler, whereby it is practically made to form an integral part of the latter.

A further feature of this invention is the provision, in the composite plate, of graphite which, owing to its comparatively speedy dissolution, quickly deposits a protective coating on that part of the interior of the boiler with which the hot water comes in plate as seen when one of the outer zinc plates has beenremoved; Fig. 2 is an edge view of the composite plate, the upper half being in section and the lower half in ele vation; and Figs. 3 and 4 illustrate two different methods of metallically connecting the composite plates to the boiler and to one another.

Referring to the drawings, a, a are the zinc plates and b the carbon plate inclosed between and in close contact with them. The zines and the carbon are drawn tightly together by means of bolts 0, c, and the composite plate is tightly secured in good metallic contact with a stud d by being forced hard up to its shoulder d by means of a nut d at one end thereof. The other end of the said stud is screw-threaded or otherwise fashioned or constructed so that it can be caused to make good and, if desired, permanent metallic contact with some suitable part of the boiler, for example, one of the plates of the shell or furnace or one of the stays of the boiler.

The Zinc plates are each preferably provided with a circumferential lip a for the purpose of more effectively preventing the entry of grease and sediment and also for the purpose of increasing the surface contact between them and the carbon plate. Further, the lip (1 increases the strength of the zinc plates and efiectually prevents any pocketing or buckling that may tend to take place notwithstanding the presence of the bolts 0. The graphitereferred to is shown at e, e, and is in the form of plugs let into holes formed in the carbon 12 during or In some cases, in carrying out this inventtidn, a copper sleeve 7', having a flange f, is interposed between the composite plate and the stud d for the purpose of providing a yielding or ductile connection between the composite plate and the stud, and improving the galvanic action.

There may, in accordance with this invention, be' any desired number of separate plates of zinc and carbon employed in making up the composite plate, and they may be of any suitable shape and dimensions to suit any given working conditions and rate of evaporation. It is found convenient in practice to employ circular platesof about 6 diameter.

- Referring now to Figs. 3 and 4, the composite plates are shown in metallic connection with the boiler shell, 9, by means of their studs 03, and. with one another by "means of copper or other conductingstrips h, which are secured by bolts h or the like in metallioconnection with opposite ends of the boiler. Any number of composite plates may be employed, according to requirements; in Fig. 3 a single pair is shown, while in Fig. 4, two such pairs are shown looped together,

'By means of the conducting strips 71., the current is more uniformly distributed throughout the boiler, so that, although the composite plates may be subjected to unequal ebullition and scouring action at different points in the boiler, their wear is equalized.

The carbon used should always be hard baked.

It will be understood that the combinatioii'of zinc, carbon, copper and iron constitutes an eflicient battery for accomplishing the objects in view.

Apparatus constructed in accordance with this invention has been put into actual practice, and it has been found that its action is so much more intense than previously proposed apparatus constructed for the same purpose, that old scale and ox dation already on the .boiler plates, including the seams,

menace and on the rivets and studs, is completely removed throughout the entire water space of the boiler, and exposes any weak or bad spots that there may be. This being so, it will be readily understood that, by this invention, any tendency to the formation of scale or to incrustation is at once counteracted.

The composite plates of this invention are so efficient that an economy in cost of some 30% to 40% is effected by their use since fewer of them are necessary than formerly.

While not wishing to confine myself to any particular theory concerning the action of my. device, it is believed that the efiect of the device is to make the boiler itself one electrode in the circuit, whereby a protecting efi'ec't is secured.

I claim:

1. Apparatus for preventing pitting or corrosion in steam boilers and the like consisting of a plate of carbonaceous material, a plate of zinc on each side of said plate and having an inturned lip or flange closely fitting to the outer edge of said plate, means for assembling and maintaining all of said plates in the manner set forth, said plates being in intimate association with one an other, substantially as described.

'2. Apparatus for preventing pitting or corrosion in steam boilers and the like consisting of a plate of carbon, graphite plugs in said carbon plate, a plate of zinc on each side of said plate of carbonand having an inturned lip or flange closely fitting to the outer edge of said plate of carbon, a stud having one end passed through said plates and provided with means for firmly securing said plates to itself and its other end adapted for metallic connection with the boiler or the like, substantially as described. In witness whereof I have hereunto set my hand in the resence of two witnesses.

C ARLES HAYTHORPE. Witnesses: H. T. P. GEE, O. J. WORTH. 

